Primary mediastinal B-cell lymphoma (PMBL) can be distinguished from diffuse large B-cell lymphoma (DLBCL) with microarray technology. We measured expression of Fcer2, Pdl2 and Blk genes and suggested a formula to discriminate PMBL from DLBCL.
Real-time quantitative polymerase chain reaction method (RTqPCR) and formalin fixed, paraffin embedded material (FFPE) were used. For 39/82 included patients the diagnosis of PMBL was expected.
Diagnosis of 10/39 and 2/43 of clinically considered PMBLs and DLBCLs, respectively, was not genetically confirmed. Compared to confirmed PMBLs, unconfirmed ones showed clinical features similar to DLBCLs, e.g. spleen infiltration (p=0,028) and decreased invasiveness in pericardium (p=0,045).
They tended to have more common infradiafragmatic involvement, less often tumor sclerosis or fluidothorax. Performed immunohistochemical staining did not discover the discordant PMBL group.
New approach of distinguishing PMBL and DLBCL is presented.